In this work, non-orthogonal multiple access (NOMA) in coordinated direct and relay transmission (CDRT) is introduced, where a base station (BS) directly communicates with user equipment 1 (UE1) ...while communicating with user equipment 2 (UE2) only through a relay. The main challenge of nonorthogonal CDRT can be solved by using the inherent property of NOMA that allows a receiver to obtain side information such as other TIE's data for interference cancellation. Analytical expressions for outage probability and ergodic sum capacity are provided. It is shown that the proposed NOMA in CDRT provides remarkable performance gain compared with NOMA in non-coordinated direct and relay transmission (nCDRT); the sum capacity scaling of the proposed scheme is log ρ b as signal-to-noise-ratio (SNR) ρ b increases, but 1/2log ρ b for NOMA in nCDRT. Exact and closed-form expressions for outage probability of each stream for UE1 and UE2 are respectively derived, and it is shown that the achievable diversity orders for each stream are same as one.
In this letter, we propose the cooperative relaying system using non-orthogonal multiple access (NOMA) to improve the spectral efficiency. The achievable average rate of the proposed system is ...analyzed for independent Rayleigh fading channels, and also its asymptotic expression is provided. In addition, a suboptimal power allocation scheme for NOMA used at the source is proposed.
The roles of rare earth elements on the texture weakening of Mg alloy are critically assessed. Two main roles are (i) the changing of stacking fault energy of Mg and (ii) the enhancement of solute ...drag of grain boundaries and dislocations. Based on this analysis, alloy design concepts and optimum process conditions for Mg alloys are suggested to increase the formability of Mg alloys.
A general multi‐ion diffusion model for liquid slag is developed for silicate melts by combining the tracer diffusivities of ions and chemical potentials from the CALculation of PHAse Diagrams ...thermodynamic database. For the demonstration of the model, the tracer diffusivities of Ca, Al, Si, and O ions in CaO–Al2O3–SiO2 melts were optimized as functions of temperature and composition using available isotope experimental data. The present model successfully simulates liquid‐junction diffusion in the CaO–Al2O3–SiO2 system and the dissolution of solid SiO2 and Al2O3 particles in CaO–Al2O3–SiO2 melts. Furthermore, the model can be readily expanded to multicomponent systems, making it potentially applicable to refractory dissolution in liquid slag and various other diffusion‐controlled high temperature processes involving liquid oxide melts.
Bridge inspection using unmanned aerial vehicles (UAV) with high performance vision sensors has received considerable attention due to its safety and reliability. As bridges become obsolete, the ...number of bridges that need to be inspected increases, and they require much maintenance cost. Therefore, a bridge inspection method based on UAV with vision sensors is proposed as one of the promising strategies to maintain bridges. In this paper, a crack identification method by using a commercial UAV with a high resolution vision sensor is investigated in an aging concrete bridge. First, a point cloud-based background model is generated in the preliminary flight. Then, cracks on the structural surface are detected with the deep learning algorithm, and their thickness and length are calculated. In the deep learning method, region with convolutional neural networks (R-CNN)-based transfer learning is applied. As a result, a new network for the 384 collected crack images of 256 × 256 pixel resolution is generated from the pre-trained network. A field test is conducted to verify the proposed approach, and the experimental results proved that the UAV-based bridge inspection is effective at identifying and quantifying the cracks on the structures.
Bee pollen consists of floral pollen mixed with bee secretions and nectar. It has been considered as a functional food and has different kinds of biologically active ingredients, such as flavonoids, ...polyphenols, phytosterols and minerals. However, its function in cognition has yet been investigated. In the present study, we investigated the ameliorating effect of bee pollen against scopolamine-caused cognitive impairment through the passive avoidance test, the Y-maze test and the Morris water maze test. In addition, Western blotting was employed to verify the effects of bee pollen on memory-related signaling molecules in the hippocampus. Bee pollen extract (100 or 300 mg/kg, per os (p.o.)) obviously reversed scopolamine-caused cognitive impairment in the passive avoidance test, ameliorated spontaneous alternation versus the scopolamine-treated group in the Y-maze test and prolonged swimming time in the target zone in the Morris water maze test. In addition, the phosphorylation levels of extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB), protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β), and the expression levels of brain-derived neurotrophic factor (BDNF) and tissue plasminogen activator (tPA) in the hippocampi, were increased in response to the treatment with bee pollen extract (100 or 300 mg/kg, p.o.). These results indicated that bee pollen ameliorates cognitive impairment induced by cholinergic blockade through the enhancing conversion of proBDNF to mature BDNF by tPA, probably, through the ERK-CREB pathway or Akt-GSK-3β signaling pathway and would be a useful agent for the treatment of cognitive dysfunction.
The CALPHAD-type computational thermodynamic databases have been developed since 1970. Several commercial computational thermodynamic software equipped with comprehensive and accurate thermodynamic ...databases and fast Gibbs energy minimization routine are widely used in the design of new materials and the optimization of materials processing. In this study, the FactSage software, which is the most frequently accessed software in high temperature materials processing, is briefly overviewed. The current databases and on-going directions of the thermodynamic database development are discussed. Application examples of FactSage thermodynamics databases to steel processing from the iron ore sintering process to the final metallic coating process are presented. Lastly, the most recent and future application of the FactSage thermodynamic databases to virtual steelmaking process simulations for the so-called industry 4.0 (smart factory) is highlighted.
The phase diagram of the Na2O–Al2O3–ZrO2 system was experimentally studied at 1500°C–1650°C by a classical equilibration/quenching method and differential thermal analysis followed by X‐ray ...diffraction phase analysis and electron probe micro‐analysis. A sealed Pt crucible was utilized to prevent the volatile loss of Na2O during high‐temperature phase equilibrium experiments and the hydration upon quenching. The phase diagram of the Na2O–Al2O3–ZrO2 system was revealed for the first time. Based on the present experimental data and available binary modeling results in literature, the thermodynamic modeling of the ternary system was performed using the Calculation of Phase Diagram method and the phase diagram of the entire the Na2O–Al2O3–ZrO2 system was constructed and the optimized thermodynamic properties for all solids and liquid phase within the ternary system were obtained.
Phase transition in nanomaterials is distinct from that in 3D bulk materials owing to the dominant contribution of surface energy. Among nanomaterials, 2D materials have shown unique phase transition ...behaviors due to their larger surface‐to‐volume ratio, high crystallinity, and lack of dangling bonds in atomically thin layers. Here, the anomalous dimensionality‐driven phase transition of molybdenum ditelluride (MoTe2) encapsulated by hexagonal boron nitride (hBN) is reported. After encapsulation annealing, single‐crystal 2H‐MoTe2 transformed into polycrystalline Td‐MoTe2 with tilt‐angle grain boundaries of 60°‐glide‐reflection and 120°‐twofold rotation. In contrast to conventional nanomaterials, the hBN‐encapsulated MoTe2 exhibit a deterministic dependence of the phase transition on the number of layers, in which the thinner MoTe2 has a higher 2H‐to‐Td phase transition temperature. In addition, the vertical and lateral phase transitions of the stacked MoTe2 with different crystalline orientations can be controlled by inserted graphene layers and the thickness of the heterostructure. Finally, it is shown that seamless Td contacts for 2H‐MoTe2 transistors can be fabricated by using the dimensionality‐driven phase transition. The work provides insight into the phase transition of 2D materials and van der Waals heterostructures and illustrates a novel method for the fabrication of multi‐phase 2D electronics.
Dimensionality‐driven anomalous phase transition of MoTe2 is demonstrated. The thinner MoTe2 has a higher 2H‐to‐Td phase transition temperature with distinct temperature differences. Vertical and lateral phase‐patterning is achieved by modulating the thickness via stacking and insertion of graphene. By using dimensionality‐driven phase transition, seamless Td contacts for 2H‐MoTe2 transistors are fabricated, leading to low contact resistance and high mobility.
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